Skid support for portable structures

ABSTRACT

A pallet-type skid support for portable structures such as for washstands and commodes. It is made from polymeric material that is abrasion resistant and resistant to moisture and rot, in contrast to wooden pallets. It includes runners that are separably attached to the platform. The platform and runners are conveniently manufactured by the rotational molding process. Indicators of runner wear may be provided.

FIELD OF THE INVENTION

A support for a portable structure such as a washstand or toilet that is resistant to wear, abrasion, incursion of moisture, rot, and splintering, and yet which is affordable and easy to maintain.

BACKGROUND OF THE INVENTION

Pallet-type supports are widely used as a base for portable structures such as washstands and enclosed toilets. They customarily provide a platform with underneath runners that create a clearance for forklift blades. This is the preferred means of moving the assembly of support and structure from location to location. However, these are also often shoved along a surface which is rough-gravel or asphalt surfaces being common. Such movements cause heavy wear on conventional runners.

The most commonly used material for such supports is wood. While wood is comparatively inexpensive, still the use of wooden pallets involves problems which need not exist. Examples of problems are the rapid splintering of wood, the incursion of water into the wood leading to rot, and the necessity of frequent repair or disposal of worn pallets and/or their runners. In addition forests are depleted by the widespread consumption of wood for pallets.

It is an object of this invention to provide a suitable support for a structure which support has moisture-impermeable outer surfaces, wear-resistant shoes inserted in the undersurface of the runners, and structural integrity as good as or better than wood.

It is another object of this invention to provide the runners as separate bodies readily attached to the platform, with their wear-resistant shoes readily replaced in the runners when they wear out, thereby to reduce wear on the runner itself and to extend the life of the runners.

It is still another object of the invention to provide a platform of substantial size that can be made with the use of rotational moulding processes.

There results a strong, affordable and sufficient skid support for a portable structure.

BRIEF DESCRIPTION OF THE INVENTION

A skid platform according to this invention includes a generally rectangular platform with a top surface to which a structure will be mounted, a bottom surface vertically spaced from the top surface, a peripheral wall between the surfaces forming a chamber, a pair of runners attached to the bottom surface spacing it from the ground, the bottom of each runner being fitted with a pair of spaced apart wear shoes which project beneath the bottom of their respective runner to take most of the wear that would otherwise wear out the runner itself.

According to a feature of this invention the runners are detachably attached to the platform, and the wear shoes are formed as inserts.

According to yet another preferred but optional feature of the invention, the platform portion of the support and the runners are formed as unitary pieces manufactured by the rotary-moulding process.

The above and other features of this invention will be fully understood from the following detailed description and the accompanying drawings, in which:

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a plan view of the presently preferred embodiment of the invention;

FIG. 2 is a side view taken at line 2-2 in FIG. 1;

FIG. 3 is an exploded view of FIG. 2;

FIG. 4 is a bottom view of FIG. 2;

FIG. 5 is a section taken at line 5-5 in FIG. 4; and

FIG. 6 is a cross-section taken at line 6-6 in FIG. 4.

DETAILED DESCRIPTION OF THE INVENTION

Support 20 includes a platform 21 and a pair of runners 22,23. Its function is to provide support for a structure 25 such as a portable toilet or washstand. These structures are well-recognized, they generally include a surrounding wall with a door. Customarily they enclose a commode or urinal and often a washstand. The functional details of the structure are arbitrary and form no necessary part of this invention. It simply rests on this support.

The platform has four sides 30, 31, 32, 33, a floor 34 (FIG. 1) and a base 35 (FIG. 4). The periphery is usually formed as a rectangle with two pairs of parallel sides.

The floor and the base are vertically spaced apart from one another over most of their areas, by outside side walls 30 (FIG. 5), and inside side walls 31. Together they form an internal chamber 36. The chamber can be filled with in-place molded structural foam 37 to provide additional structural strength to the support. Otherwise the wall thickness and dimensions of the platform and the structural qualities of their material will be relied on.

The floor is pierced by a rectangular opening 40 (FIG. 1) with a tapered wall 41. This arrangement enables tanks or receptacles to be held in place, where they can be supplied with water, for example, or receive fluids or other substances which are later to be pumped out.

Adjacent to opening 40 there is a substructural planar stand area 42 of the floor for the user to stand on. Usually this will be a continuous flat surface. If desired, some or all of it can be cut out and covered with a grating or screen (not shown). This enables dirt and mud on the user's shoes to be scraped off and fall into region 44 between the runners.

Base 35 (FIGS. 5 and 6) will preferably be provided with a set of linear grooves 45 between sidewalls. Threaded sockets 46 are implanted in the platform, opening onto the bottom surface near the corners for a purpose to be described.

Runners 22 and 23 are identical so only runner 22 will be described in detail. It is an elongated member with a top surface 50 formed with a tongue 51 that fits in a respective groove 45 in the bottom surface of the sides of the platform. This tongue-in-groove arrangement holds the runner aligned with the edge of the platform. The top surface on each side engages the bottom surface of the platform on both sides of the groove. The runners are thereby held aligned and in place.

The bottom surface 52 of each runner faces the ground 53. Sidewalls of the runner join the top and bottom surfaces of the runner to form a chamber 56. A structural foam 57 is preferably formed in place in this chamber to give additional strength to the runners.

Each runner has an attachment flange 60,61 (FIG. 3) at each end. Each flange includes a bearing surface 62 on which some part of the structure can rest. A bolt hole 63 passes a bolt 63 a that is threaded upwardly into the structure to hold the structure to the runner. It is possible to make the flange a part of the platform instead, and such an arrangement is contemplated by this invention. However it is much easier to provide it as part of the runner when the runner is made with processes preferred in this invention. The flange also acts as a closure for the ends of the runner.

The materials of construction of this support provide substantial and certainly adequate wall, column and beam strength to support the structure, both when it rests on the ground, and when a forklift lifts it between the runners. The basic material of construction is an organic plastic which is impermeable to water. However, its abrasive resistance is less that one would prefer. Structures such as these are often shoved along a very rough surface. This is one reason why wooden runners require such frequent maintenance.

To overcome this disadvantage, each runner is provided with a pair of “wear shoes” 70. Each shoe has a tapered outer periphery 71, a wear surface 72, and a bolt hole 73 passing axially through it. Significantly, the socket 74 into which the shoe fits has a matching tapered hole 75 aligned with a port 76 in the bottom of the platform.

Inside port 76 there is a cast-in-place or an embedded threaded receptacle. To mount the shoe, one merely inserts a bolt 63 a through hole 75 and threads the bolt into the receptacle. That is all. This both removably attaches the shoe and holds the runner to the platform. The head 78 of the bolt fits in a recess 79 in the shoe so that it is not contacted directly by the ground. A raised rim 80 on the face of the shoe can provide for first wear. When it is ground down, it is visually apparent that a replacement shoe will soon be needed.

Preferably the shoes are made with a vivid color such as a bright yellow that contrasts with a black runner. Their wear will then be more evident.

An engagement grove 85 is formed in the bottom of engagement flange 60 for engagement by a hook or cable for lifting the assembly, instead of rasing it by a forklift.

An examination of the drawings will show that the shape of the platform and runners are so complicated that it would not be affordable if made by most common manufacturing techniques. Instead, because it is amenable to use of rotational moulding process, the platform can be made in single piece. Also each runner can be made as a single piece. They are hollow structures which can be filled with a structural foam either while the outer wall is being formed, or after they are formed.

As such these runners provide a sufficient volumetric device to enable the use of forklifts and to hold the structure above the ground. Conventional pallets do this by nailing together pieces of wood with all of their costs and disadvantages.

The process known as rotational moulding, or sometimes “slush moulding”, is characterized by the use of a hollow mold whose inside surfaces are intended to be the mirror image of the surfaces formed against them. In practice, the mold shaped is closed after a sufficient amount of a plastic to be molded is put inside.

Then the mold is heated and rotated appropriately around axes of rotation. The organic plastic material is melted, and flows around the inside wall of the mold. After a sufficient length of time, the plastic will have been distributed and ready to be cured. The mold is allowed to cool, and is separated, and the product is removed. It is, of course, a hollow product.

Either as a secondary operation or a part of the initial formation, a foaming product is placed in the mold, where it forms a structural foam inside the molded structure. These techniques are well-known in the art.

Variations in the wall thickness, and localized thicker areas can be provided for by appropriate insulation on the tooling so that additional material will be deposited locally. Also, implants such as sockets can be placed in the tooling so they will be incorporated into the structure.

The wall thicknesses and structural strength of the materials are known so that a suitably strong structure will be made.

Any suitable heat curable organic plastic can be used which has sufficient strength properties. Polyethylene and polybutylene are commonly used.

This invention is not to be limited by the embodiment shown in the drawings and described in the description, which is given by way of example and not of limitation, but only in accordance with the scope of the appended claims. 

1. A support to mount a portable structure above the surface of the ground, said support comprising: a platform having a top surface, a bottom surface, four peripheral outer sidewalls, and four inside sidewalls, said outer sidewalls being integral with said top and bottom surfaces, thereby spacing them apart, said inner sidewalls being parallel to and spaced apart from respective sidewalls, integral with said top and bottom surfaces, thereby forming a peripheral chamber bounded by said sidewalls and the top and bottom surfaces; a groove in said bottom surface parallel to at least one parallel pair of said outer sidewalls; a pair of runners, each runner comprising a top surface, a bottom surface, a pair of sidewalls and a pair of end closures, said surfaces, sidewalls and end closures forming a prismatic body enclosing a chamber, and a mounting pad at each end to engage said portable structure; a tongue on the top surface of said runner so disposed and arranged as to fit into a respective groove in the bottom surface of the platform; said runners having a pair of sockets opening onto the bottom surface of the runner, said sockets being tapered, with a central opening; a wear shoe for each said socket, said wear shoe being tapered to fit into said socket with a flange to bear against the bottom surface of the runner, and a thickness sufficient to space the wear surface from the bottom surface of the runner; a bolt which includes a head, a shank and a thread for each insert, said bolt being passed through said insert with its head bearing against the wear shoe and its thread threaded into said platform, thereby attaching the wear shoe to the runner and the runner to the platform; the top and bottom surfaces and sidewalls of the platform being integral and continuous with one another, created by the rotational moulding process; the top and bottom surfaces and sidewalls of the runners being integral and continuous with one another, created by the rotational moulding process.
 2. A support according to claim 1 in which the top surface of the platform includes a recess to receive a container, and a stand on which a person can stand.
 3. A support according to claim 1 in which the top surface of the platform includes a recess to receive a container, an open region, and a grating to overlay the open region on which a person can stand, but through which dirt can fall.
 4. A support according to claim 1 in which the color of the shoe contrasts with the color of the runner to provide evidence of wear.
 5. A support according to claim 2 in which said bottom surface of said platform in the region directly beneath said stand is closer to the stand than the remainder of the bottom surface. 